1 #ifndef _LINUX_SEM_H
2 #define _LINUX_SEM_H
3
4 #include <linux/ipc.h>
5
6 /* semop flags */
7 #define SEM_UNDO 0x1000 /* undo the operation on exit */
8
9 /* semctl Command Definitions. */
10 #define GETPID 11 /* get sempid */
11 #define GETVAL 12 /* get semval */
12 #define GETALL 13 /* get all semval's */
13 #define GETNCNT 14 /* get semncnt */
14 #define GETZCNT 15 /* get semzcnt */
15 #define SETVAL 16 /* set semval */
16 #define SETALL 17 /* set all semval's */
17
18 /* ipcs ctl cmds */
19 #define SEM_STAT 18
20 #define SEM_INFO 19
21
22 /* Obsolete, used only for backwards compatibility and libc5 compiles */
23 struct semid_ds {
24 struct ipc_perm sem_perm; /* permissions .. see ipc.h */
25 __kernel_time_t sem_otime; /* last semop time */
26 __kernel_time_t sem_ctime; /* last change time */
27 struct sem *sem_base; /* ptr to first semaphore in array */
28 struct sem_queue *sem_pending; /* pending operations to be processed */
29 struct sem_queue **sem_pending_last; /* last pending operation */
30 struct sem_undo *undo; /* undo requests on this array */
31 unsigned short sem_nsems; /* no. of semaphores in array */
32 };
33
34 /* Include the definition of semid64_ds */
35 #include <asm/sembuf.h>
36
37 /* semop system calls takes an array of these. */
38 struct sembuf {
39 unsigned short sem_num; /* semaphore index in array */
40 short sem_op; /* semaphore operation */
41 short sem_flg; /* operation flags */
42 };
43
44 /* arg for semctl system calls. */
45 union semun {
46 int val; /* value for SETVAL */
47 struct semid_ds *buf; /* buffer for IPC_STAT & IPC_SET */
48 unsigned short *array; /* array for GETALL & SETALL */
49 struct seminfo *__buf; /* buffer for IPC_INFO */
50 void *__pad;
51 };
52
53 struct seminfo {
54 int semmap;
55 int semmni;
56 int semmns;
57 int semmnu;
58 int semmsl;
59 int semopm;
60 int semume;
61 int semusz;
62 int semvmx;
63 int semaem;
64 };
65
66 #define SEMMNI 128 /* <= IPCMNI max # of semaphore identifiers */
67 #define SEMMSL 250 /* <= 8 000 max num of semaphores per id */
68 #define SEMMNS (SEMMNI*SEMMSL) /* <= INT_MAX max # of semaphores in system */
69 #define SEMOPM 32 /* <= 1 000 max num of ops per semop call */
70 #define SEMVMX 32767 /* <= 32767 semaphore maximum value */
71
72 /* unused */
73 #define SEMUME SEMOPM /* max num of undo entries per process */
74 #define SEMMNU SEMMNS /* num of undo structures system wide */
75 #define SEMAEM (SEMVMX >> 1) /* adjust on exit max value */
76 #define SEMMAP SEMMNS /* # of entries in semaphore map */
77 #define SEMUSZ 20 /* sizeof struct sem_undo */
78
79 #ifdef __KERNEL__
80
81 /* One semaphore structure for each semaphore in the system. */
82 struct sem {
83 int semval; /* current value */
84 int sempid; /* pid of last operation */
85 };
86
87 /* One sem_array data structure for each set of semaphores in the system. */
88 struct sem_array {
89 struct kern_ipc_perm sem_perm; /* permissions .. see ipc.h */
90 time_t sem_otime; /* last semop time */
91 time_t sem_ctime; /* last change time */
92 struct sem *sem_base; /* ptr to first semaphore in array */
93 struct sem_queue *sem_pending; /* pending operations to be processed */
94 struct sem_queue **sem_pending_last; /* last pending operation */
95 struct sem_undo *undo; /* undo requests on this array */
96 unsigned long sem_nsems; /* no. of semaphores in array */
97 };
98
99 /* One queue for each sleeping process in the system. */
100 struct sem_queue {
101 struct sem_queue * next; /* next entry in the queue */
102 struct sem_queue ** prev; /* previous entry in the queue, *(q->prev) == q */
103 struct task_struct* sleeper; /* this process */
104 struct sem_undo * undo; /* undo structure */
105 int pid; /* process id of requesting process */
106 int status; /* completion status of operation */
107 struct sem_array * sma; /* semaphore array for operations */
108 int id; /* internal sem id */
109 struct sembuf * sops; /* array of pending operations */
110 int nsops; /* number of operations */
111 int alter; /* operation will alter semaphore */
112 };
113
114 /* Each task has a list of undo requests. They are executed automatically
115 * when the process exits.
116 */
117 struct sem_undo {
118 struct sem_undo * proc_next; /* next entry on this process */
119 struct sem_undo * id_next; /* next entry on this semaphore set */
120 int semid; /* semaphore set identifier */
121 short * semadj; /* array of adjustments, one per semaphore */
122 };
123
124 asmlinkage long sys_semget (key_t key, int nsems, int semflg);
125 asmlinkage long sys_semop (int semid, struct sembuf *sops, unsigned nsops);
126 asmlinkage long sys_semctl (int semid, int semnum, int cmd, union semun arg);
127
128 #endif /* __KERNEL__ */
129
130 #endif /* _LINUX_SEM_H */
131
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